Why don’t the seasons in the Northern and Southern Hemispheres coincide?

The change of seasons is explained by the rotation of the Earth around the Sun, moreover, that the axis of our planet is at an angle of 66.56 ° to the orbital plane. The result is cyclical, annual fluctuations in the length of the day, as well as the height of the sun above the horizon. And as a result, there is an annual, cyclical distribution of heat in the hemispheres so that when the cold season is south of the equator, it is warm to the north.